JP5576829B2 - Compound, polymer containing the same, and chemically amplified resist composition containing the polymer - Google Patents

Description

  The present invention relates to a compound, a polymer containing the compound, and a chemically amplified resist composition containing the polymer. The present invention relates to a novel compound and a polymer obtained by polymerizing the compound as a monomer to uniformly distribute the composition. It is suitable for forming fine patterns, reduces the amount of gas generation, has characteristics such as high adhesive strength, high sensitivity, and high thermal stability, and improves resolution and LER (line edge roughness). be able to. In addition, pattern formation is possible using various types of radiation such as far-infrared rays such as KrF excimer laser and ArF excimer laser, X-rays such as synchrotron radiation, and charged particle beams such as electron beams (e-beams). The present invention relates to a novel compound which can be used for the preparation of an effective resist, a polymer obtained by polymerizing the compound, and a chemically amplified resist composition containing the compound.

  Recently, with the development of lithography technology used in the semiconductor industry or the like to a technology of 50 nanometers or less, it is expected that a further advanced new technology will appear. Lithography technology using EUV is an important technology that enables such patterning, and technology that enables a pattern of 32 nanometers or less is a very difficult task. Lithography technology using a 193 nm wavelength is an important means to enable a pattern technology of 32 nanometers or less in the future. However, when the numerical aperture (NA) is increased, the technology is reduced to 32 nanometers or less. Pattern technology is also possible.

  According to the Rayleigh equation, the numerical aperture can be increased to increase the refractive index of the immersion fluid or the immersion resist, and the resolution can be improved at the same time. The DOF can also be increased by increasing the refractive index.

  In order to improve physical properties such as resolution, sensitivity, refractive index, and LER, there is a continuous demand for new resist compositions, and research on resist technology having high sensitivity by increasing the refractive index of current resists has been conducted. It has been broken. However, the result of such research is not sufficient for realizing an increasingly miniaturized semiconductor integrated circuit, and there is a problem that the development speed (photospeed) is slow.

  In addition, it is possible to add a large amount of photoacid generator, and there is an increasing demand for a chemically amplified resist composition having high speed sensitivity and high stability, reducing gas discharge, high resolution and low LER. ing.

  An object of the present invention is to provide a novel compound that can be used as a photoacid generator or a monomer in a chemically amplified resist. Also provided is a polymer containing the above compound as a monomer that can be used in a chemically amplified resist composition having a high resolution and a low LER while reducing gas discharge while having excellent sensitivity and high stability. There is to do.

  In order to achieve the above object, a compound according to an embodiment of the present invention is represented by Formula 1.

In the formula, R ₁₁ is any one selected from the group consisting of hydrogen, alkyl having 1 to 10 carbons, perfluoroalkyl having 1 to 10 carbons, and an alkoxy group having 1 to 10 carbons, Q ₁ and Q ₂ are each independently one selected from the group consisting of hydrogen and halogen atoms, and A + is an organic counter ion.

  A polymer according to another embodiment of the present invention includes a repeating unit represented by Formula 2 below.

In the above formula, each of R ₁₁ , R ₄₁ and R ₄₂ is independently selected from the group consisting of hydrogen, alkyl having 1 to 10 carbons, perfluoroalkyl having 1 to 10 carbons, and alkoxy having 1 to 10 carbons. Q ₁ and Q ₂ are each independently one selected from the group consisting of hydrogen and halogen atoms, and A + is an organic counter ion.

  The polymer may be represented by the following chemical formula 3.

In the above formula, R ₁₁ , R ₁₂ , R ₁₃ , R ₁₄ , R ₄₁ , R ₄₂ , R ₄₃ , R ₄₄ , R ₄₅ , R ₄₆ , R ₄₇ and R ₄₈ are each independently hydrogen, carbon number 1 -10 alkyl, a C 1-10 perfluoroalkyl, and a C 1-10 alkoxy group, and each of Q ₁ and Q ₂ independently represents hydrogen and halogen. Any one selected from the group consisting of atoms, wherein R ₂₁ , R ₂₂ and R ₂₃ are each independently hydrogen, an alkyl group, a heteroalkyl group, a cycloalkyl group, a heterocycloalkyl group, an aryl group, a hetero group; Any one selected from the group consisting of an aryl group and a combination thereof, the A + is an organic counter ion, the X is a polymerized unit derived from an olefin monomer, and the l, m, n, o, and p are 0 <l ≦ 0.4, 0 <m ≦ 0.5, 0 ≦ n ≦ 0.5, 0 ≦ o ≦ 0.5, 0 <p ≦ 0.2, and l + m + n + o + p = 1. .

  The polymer may have a weight average molecular weight of 2,000 to 100,000 and a molecular weight distribution of 1 to 5.

  A chemically amplified resist composition according to another embodiment of the present invention includes a polymer including the repeating unit represented by Formula 2.

  Hereinafter, the present invention will be described in more detail.

  Definitions of terms used in the present specification are as follows.

  Unless otherwise specified in the present specification, a halogen atom means any one selected from the group consisting of fluoro, chlorine, bromine, and iodo.

  Unless stated otherwise specifically in the specification, alkyl groups include primary alkyl groups, secondary alkyl groups, and tertiary alkyl groups.

  Unless otherwise specified in this specification, a perfluoroalkyl group means an alkyl group in which some hydrogen atoms or all hydrogen atoms are substituted with fluoro.

  Unless otherwise specified in this specification, a perfluoroalkoxy group means an alkoxy group in which some hydrogen atoms or all hydrogen atoms are substituted with fluoro.

  Unless otherwise stated herein, all compounds or substituents can be substituted or unsubstituted. Here, the substitution means that hydrogen is a halogen atom, hydroxy group, carboxy group, cyano group, nitro group, amino group, thio group, methylthio group, alkoxy group, nitrile group, aldehyde group, epoxy group, ether group, ester group , Carbonyl group, acetal group, ketone group, alkyl group, perfluoroalkyl group, cycloalkyl group, heterocycloalkyl group, allyl group, benzyl group, aryl group, heteroaryl group, derivatives thereof and combinations thereof It means an alternative to any one selected.

  Unless stated otherwise specifically in the specification, the prefix hetero means that 1 to 3 heteroatoms selected from the group consisting of N, O, S and P have substituted carbon atoms. For example, a heteroalkyl group means that the hetero atom has substituted 1-3 carbon atoms in the carbon atom of an alkyl group.

  Unless otherwise specified in this specification, an alkyl group is a linear or branched alkyl group having 1 to 30 carbon atoms, a heteroalkyl group is a heteroalkyl group having 1 to 3 carbon atoms, and an alkoxy group is 1 to 10 carbon atoms. An alkoxy group, a perfluoroalkyl group is a perfluoroalkyl group having 1 to 10 carbon atoms, a perfluoroalkoxy group is a perfluoroalkoxy group having 1 to 10 carbon atoms, a cycloalkyl group is a cycloalkyl group having 3 to 32 carbon atoms, and a heterocycloalkyl group is A heterocycloalkyl group having 2 to 32 carbon atoms, an aryl group means an aryl group having 6 to 30 carbon atoms, and a heteroaryl group means a heteroaryl group having 2 to 30 carbon atoms.

  Unless stated otherwise specifically in the specification, cycloalkyl groups include monocyclic, bicyclic, tricyclic, and tetracyclic. Also included are polycyclic cycloalkyl groups including adamantyl group, norbornyl group, norbornyl group.

  Unless otherwise specified in this specification, an aryl group means a compound containing a benzene ring and derivatives thereof, for example, two or more benzene rings formed by a single bond, such as toluene or xylene having an alkyl side chain on the benzene ring. It may be naphthalene or anthracene in which two or more benzene rings are condensed, such as fluorene, xanthene, or anthraquinone in which two or more benzene rings are bonded via a cycloalkyl group or heterocycloalkyl group, such as bonded biphenyl.

  Unless stated otherwise herein, olefin means an unsaturated hydrocarbon compound containing a double bond. For example, it may be alkylene, acrylate, styrene, norbornene, indene, acenaphthylene, flange-on and the like, but is not limited thereto.

  The compound of one example of the present invention is represented by the following chemical formula 1.

In the above formula,
R ₁₁ is any one selected from the group consisting of hydrogen, alkyl having 1 to 10 carbons, perfluoroalkyl having 1 to 10 carbons and alkoxy having 1 to 10 carbons, preferably hydrogen, trimethyl It may be any one selected from fluoromethyl, an alkyl group having 1 to 5 carbon atoms and an alkoxy group having 1 to 5 carbon atoms.

Q ₁ and Q ₂ are each independently any one selected from the group consisting of hydrogen and halogen atoms, preferably fluoro.

  A + is an organic counter ion.

  The organic counter ion may be represented by the following chemical formula 5 or the following chemical formula 6.

In the above formula,
R ₁ , R ₂ and R ₃ are each independently one selected from the group consisting of an alkyl group, a heteroalkyl group, a perfluoroalkyl group, an alkoxy group, an aryl group, and a heteroaryl group.

In the above formula,
R ₄ and R ₅ are each independently any one selected from the group consisting of an alkyl group, a heteroalkyl group, a perfluoroalkyl group, an alkoxy group, an aryl group, and a heteroaryl group.

  The chemical formula 5 may be any one selected from the group consisting of the following chemical formulas 5-i to 5-xxii.

  The chemical formula 6 may be any one selected from the group consisting of the following chemical formulas 6-i to 6-ix.

  The compound of Formula 1 is a monomer and serves as a photoacid generator. At this time, by adjusting the number of carbon atoms in the main chain of the compound, a space where the acid generated by exposure can be diffused from a polymer obtained by polymerizing the compound as a monomer is secured, and the acid diffusion distance is appropriately set during patterning. Adjustments can be made to improve resolution and LER characteristics.

  A polymer according to another embodiment of the present invention includes a repeating unit represented by Formula 2 below.

In the above formula,
R ₁₁ , R ₄₁ and R ₄₂ are each independently one selected from the group consisting of hydrogen, alkyl having 1 to 10 carbons, perfluoroalkyl having 1 to 10 carbons and alkoxy having 1 to 10 carbons. Preferably, it may be any one selected from hydrogen, trifluoromethyl, an alkyl group having 1 to 5 carbon atoms and an alkoxy group having 1 to 5 carbon atoms.

Q ₁ and Q ₂ are each independently any one selected from the group consisting of hydrogen and halogen atoms, preferably fluoro.

  A + is an organic counter ion. Since the description regarding A + is the same as the description of Chemical Formula 1, the description thereof is omitted.

  The polymer directly polymerizes the compound of Formula 1 that serves as a photoacid generator into the polymer, thereby allowing a large amount of photoacid generator to be added. Thus, the amount of exhaust gas generated after exposure is reduced, and a polymer having a low LER is produced.

  The polymer may be a multi-component copolymer and may be a block copolymer, a random copolymer, or a graft copolymer. In addition, the polymer including the repeating unit represented by the chemical formula 2 includes a repeating unit having an acid labile group, a repeating unit including a hydroxy group, a repeating unit including an adhesive group of a lactone ring, and a combination thereof. It may contain any one repeating unit selected.

  More specifically, the polymer may be represented by the following chemical formula 3.

In the above formula,
R ₁₁ , R ₁₂ , R ₁₃ , R ₁₄ , R ₄₁ , R ₄₂ , R ₄₃ , R ₄₄ , R ₄₅ , R ₄₆ , R ₄₇ and R ₄₈ are each independently hydrogen, alkyl having 1 to 10 carbons, Any one selected from the group consisting of a C 1-10 perfluoroalkyl and a C 1-10 alkoxy group, preferably hydrogen, trifluoromethyl, a C 1-5 alkyl group and a carbon number It may be any one selected from 1 to 5 alkoxy groups.

Q ₁ and Q ₂ are each independently any one selected from the group consisting of hydrogen and halogen atoms, preferably fluoro.

  The A + is an organic counter ion, and the description of the A + is the same as the description of A + in the chemical formula 1, and therefore the description thereof is omitted.

  The l, m, n, o and p are 0 <l ≦ 0.4, 0 <m ≦ 0.5, 0 ≦ n ≦ 0.5, 0 ≦ o ≦ 0.5, 0 <p ≦ 0. 2 and l + m + n + o + p = 1.

  X is a polymerized unit derived from an olefin monomer.

  The olefin monomer is preferably selected from the group consisting of acrylate, styrene, norbornene, indene, acenaphthylene, flangeone, and derivatives thereof. It can be any one of them.

  The -X- may be a polymer unit represented by the following chemical formulas 3-a to 3-f.

In the above formula,
R ₁₅ , R ₄₉ and R ₅₀ are any one selected from the group consisting of hydrogen, an alkyl group having 1 to 10 carbon atoms, a perfluoroalkyl group having 1 to 10 carbon atoms and an alkoxy group having 1 to 10 carbon atoms. Preferably, it may be any one selected from hydrogen, trifluoromethyl, an alkyl group having 1 to 5 carbon atoms, and an alkoxy group having 1 to 5 carbon atoms.

R ₃₁ and R ₃₂ are each independently a halogen atom, hydroxy group, cyano group, carboxy group, nitrile group, aldehyde group, epoxy group, nitro group, amino group, thio group, methylthio group, alkyl group, alkoxy group, perfluoro It is any one selected from the group consisting of an alkoxy group, a hydroxyalkyl group, a cycloalkyl group, a heterocycloalkyl group, an aryl group, a heteroaryl group, COOR ′ and COR ′. R ′ is any one selected from the group consisting of an alkyl group, a perfluoroalkyl group, a cycloalkyl group, an aryl group, and a cycloaryl group.

  The a is an integer of 0 to 5, the b is an integer of 0 to 5, the c is an integer of 0 to 8, the d is an integer of 0 to 4, and the e is 0 to 3 F is an integer of 0 to 3.

In Formula 3,
R ₂₁ , R ₂₂ and R ₂₃ are each independently selected from the group consisting of hydrogen, alkyl groups, heteroalkyl groups, cycloalkyl groups, heterocycloalkyl groups, aryl groups, heteroaryl groups, and combinations thereof. 1 and preferably any one selected from the group consisting of the following chemical formulas 3-i to 3-ix.

In the above formula,
R _{33 to} R ₃₅ are each independently hydrogen, alkyl group, alkoxy group, perfluoroalkyl group, perfluoroalkoxy group, hydroxyalkyl group, halogen atom, hydroxy group, cyano group, nitro group, amino group, thio group, methylthio group. , An ether group, and a methoxy group, and preferably R _{33 to} R ₃₅ are each independently hydrogen, an alkyl group having 1 to 6 carbon atoms, or an alkyl group having 1 to 6 carbon atoms. Alkoxy group, perfluoroalkyl group having 1 to 4 carbon atoms, perfluoroalkoxy group having 1 to 4 carbon atoms, hydroxyalkyl group having 1 to 6 carbon atoms, halogen atom, hydroxy group, cyano group, nitro group, amino group, thio group And any one selected from the group consisting of a methylthio group and a methoxy group.

  G is an integer of 0-9, h is an integer of 0-9, i is an integer of 0-5, j is an integer of 0-15, and k is 0-15. Q is an integer of 0 to 17, and r is an integer of 0 to 11.

  The polymer may be one represented by the following chemical formula 4.

In the above formula, R ₁₁ , R ₁₂ , R ₁₃ , R ₁₄ , R ₄₁ , R ₄₂ , R ₄₃ , R ₄₄ , R ₄₅ , R ₄₆ , R ₄₇ , R ₄₈ , Q ₁ , Q ₂ , A +, R ₂₁ , R ₂₂ , R ₂₃ , l, m, n, o, and p are the same as in the description of Chemical Formula 3, and the description thereof is omitted.

  In the formula, b is an integer of 0 to 5, and c is an integer of 0 to 8.

In the formula, each of R ₁₅ and R ₄₉ is independently selected from the group consisting of hydrogen, alkyl having 1 to 10 carbons, perfluoroalkyl having 1 to 10 carbons, and alkoxy having 1 to 10 carbons. Preferably, R ₁₅ and R ₄₉ are each independently selected from hydrogen, trifluoromethyl, an alkyl group having 1 to 5 carbon atoms, and an alkoxy group having 1 to 5 carbon atoms. It can be.

In the above formula, R ₃₁ is a halogen atom, hydroxy group, cyano group, carboxy group, nitrile group, aldehyde group, epoxy group, nitro group, amino group, thio group, methylthio group, alkyl group, alkoxy group, perfluoroalkoxy group. , Hydroxyalkyl group, cycloalkyl group, heterocycloalkyl group, aryl group, heteroaryl group, COOR ′ and COR ′. R ′ is any one selected from the group consisting of an alkyl group, a perfluoroalkyl group, a cycloalkyl group, an aryl group, and a cycloaryl group.

R ₃₁ is preferably an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a perfluoroalkyl group having 1 to 4 carbon atoms, a perfluoroalkoxy group having 1 to 4 carbon atoms, or 1 to 6 carbon atoms. Any one selected from the group consisting of a hydroxyalkyl group, a halogen atom, a hydroxy group, a cyano group, a nitro group, an amino group, a thio group, and a methylthio group, and more preferably R ₃₁ is hydrogen and It may be any one selected from the group consisting of Chemical Formula 3-x.

  When a resist is produced with a polymer containing a (meth) acrylic polymer, the amount of light absorption is small, but there is a disadvantage that the etching resistance is inferior to that of an aromatic compound. However, when it is introduced into the main chain together with a cyclic olefin having a larger number of carbon atoms than the (meth) acrylic polymer as in the chemical formula 4, the etching resistance is improved, and the portion that is cut by the acid is subjected to pre-treatment (Soft Baking). It will not be vaporized later and will remain in the resist film, thereby improving the fluidity of the acid emitted from the acid generator during exposure, thereby improving the patterning characteristics.

  The polymer may be any one selected from the group consisting of the following chemical formulas 4-a to 4-l.

In the above formula,
The l, m, n, o and p are 0 <l ≦ 0.4, 0 <m ≦ 0.5, 0 ≦ n ≦ 0.5, 0 ≦ o ≦ 0.5, 0 <p ≦ 0. 2 and l + m + n + o + p = 1.

  Since A + is an organic counter ion and is the same as the description of A + in Chemical Formula 1, the description thereof is omitted.

  The polymer containing the repeating unit of Formula 2 preferably has a polystyrene-equivalent weight average molecular weight of 2,000 to 100,000 and a molecular weight distribution of 1 to 5, more preferably 3 by gel permeation chromatography (GPC). The molecular weight distribution can be from 1.50 to 30,000. If the weight average molecular weight exceeds 100,000, the solubility and LER may be poor when used in a photoresist composition, and if it is less than 2,000, the mechanical strength of the resin is poor. A phenomenon that a pattern cannot be formed smoothly (pattern collapse) occurs. When the molecular weight distribution exceeds 5, the LER may be inferior. Therefore, when the polymer having the above-mentioned weight average molecular weight and molecular weight distribution range is used for the photoresist composition, the developability, the coating property, and the heat resistance have good physical properties.

  The compound represented by Formula 1 is produced by the following method.

  The compound represented by the chemical formula 1 replaces the compound represented by the following chemical formula 9 with the first step in which the compounds represented by the chemical formula 7 and the chemical formula 8 are reacted, and the reaction product prepared in the first step. It can be produced by the second stage of reaction.

In the above formula,
The M + is any one selected from the group consisting of Li +, Na +, and K +.

Wherein Z- is _{(OSO 2 CF 3) -,} (OSO 2 C 4 F 9) -, (OSO 2 C 8 F 17) -, (N (CF 3) 2) -, (N (C 2 F 5) _{2) -, (N (C} 4 F 9) 2), (C (CF 3) 3) -, (C (C 2 F 5) 3) -, (C (C 4 F 9) 3) -, F -, Cl-, Br-, I-, BF 4 -, AsF 6 -, and PF ₆ - is any one selected from the group consisting of,
Since the description regarding A +, R ₁₁ , Q ₁ and Q ₂ is the same as the description of the compound represented by Chemical Formula 1, the description thereof is omitted.

  The first stage reaction is performed in a solvent, and the solvent is any one selected from the group consisting of esters, ethers, lactones, ketones, amides, alcohols, and combinations thereof. Preferably, dichloromethane, chloroform, dichloroethane, acetonitrile, toluene, benzene, 1,4-dioxane and the like can be used.

  The first stage reaction is performed with a basic catalyst, and the basic catalyst is any one selected from the group consisting of triethylamine, diethylamine, pyridine, diethylisopropylamine, aniline, diisopropylethylamine, and combinations thereof. It can be. When the first stage reaction is performed together with the basic catalyst, the reaction time can be shortened, the conversion yield can be increased, and the side reaction can be reduced.

  The compound represented by the chemical formula 8 is obtained by reducing a compound represented by the following chemical formula 10.

In the above formula,
The M + is any one selected from the group consisting of Li +, Na + and K +.

R ₆ is any one selected from the group consisting of hydrogen, an alkyl group having 1 to 10 carbon atoms, and a heteroalkyl group in which hydrogen 1 to 3 in the alkyl group having 1 to 10 carbon atoms is substituted with a halogen atom. It may be any one selected from the group consisting of hydrogen, an alkyl group having 1 to 5 carbon atoms, trifluoromethyl, trichloromethyl, tribromomethyl, and triiodomethyl.

Since the explanation about Q ₁ and Q ₂ is the same as the explanation of the compound represented by Chemical Formula 1, the description is omitted.

  The process of reducing the compound represented by Formula 10 to obtain the compound represented by Formula 8 is specifically performed by dissolving the compound represented by Formula 8 in tetrahydrofuran and an alcoholic solvent under an ice bath. A reducing agent is slowly added dropwise, and after completion of the dropwise addition, the reaction mixture is heated to 40 to 100 ° C., reacted with stirring, the reaction of the reaction mixture is terminated, and the solvent is removed. A process of removing and crystallizing may be included. Examples of the crystallization method include a normal crystallization method. Specifically, the reaction mixture from which the solvent has been removed is acidified to a pH of 5 to 6 using a strong acid, and after concentration, a slurry is added with alcohol. And the filtrate is washed with hexane, concentrated again, and crystallized with diethyl ether.

  The polymer containing the repeating unit of Chemical Formula 2 is polymerized by an ordinary method for producing a polymer, and a radical polymerization method is preferable. Examples of the polymerization initiator used in the radical polymerization include azobisisobutyronitrile (AIBN), benzoyl peroxide (BPO), lauryl peroxide, azobisisocapronitrile, azobisisovaleronitrile, tert-butyl. Any one selected from the group consisting of hydroperoxides and combinations thereof can be used. The polymerization reaction of the polymerization can be carried out by a method such as bulk polymerization, solution polymerization, suspension polymerization, bulk-suspension polymerization, emulsion polymerization, and the polymerization solvent used for the polymerization includes benzene, toluene, xylene, One or more of halogenated benzene, diethyl ether, tetrahydrofuran, 1,2-dichloroethane, esters, ethers, lactones, ketones and amides can be selected and used. After the polymerization is completed, unreacted monomers and by-products remaining in the reaction mixture can be removed by a usual method for removing them, and preferably by a precipitation method using a solvent.

  A chemically amplified resist composition according to another embodiment of the present invention includes a polymer including the repeating unit represented by Formula 2. In the polymer, the amount of the monomer represented by Chemical Formula 1 is 0.5 to 15 parts by weight with respect to 100 parts by weight of the solid component of the whole polymer, When the monomer represented by Chemical Formula 1 is used, it has further excellent sensitivity and high stability, and can reduce gas discharge.

  The resist composition may include 3% by weight or more, preferably 5% by weight or more of the polymer including the repeating unit of Formula 2 with respect to the total resist composition. If the content of the polymer is less than 3% by weight, the effect of the polymer may not be sufficiently obtained. In addition to the polymer, the resist composition may include components constituting an ordinary resist composition such as an additive and a solvent.

  The resist composition including the repeating unit of Chemical Formula 2 includes a step of applying the resist composition on a substrate, a step of heat-treating the applied resist composition and exposing it to high energy rays, and a developer. Then, a pattern can be formed by a pattern forming method including a step of developing.

  The high energy ray has a wavelength in the range of 13.5 nm to 250 nm, thereby obtaining high resolution and low LER.

  The novel compound according to the present invention and a polymer containing the compound have excellent sensitivity and high stability when used in a chemically amplified resist composition, can reduce gas discharge, have high resolution, and have low LER. Is obtained.

  Hereinafter, embodiments of the present invention will be described in detail so that a person having ordinary knowledge in the technical field to which the present invention belongs can be easily implemented. However, the present invention can be realized in various forms, and is not limited to the embodiments described herein.

<Examples of compound synthesis>
1) Synthesis of difluorohydroxypropane sulfonic acid sodium salt 3,3-difluoro-3-sulfopropionic acid sodium salt in an ice bath (3,3-difluoro-3-sulfopropionic acid) 83 g of ester sodium salt) was dissolved in 160 ml of methanol and 1.2 L of THF, and 44 g of sodium borohydride (NaBH ₄ ) was slowly added dropwise. After removing the ice bath, the reaction mixture after completion of the dropwise addition was heated and stirred at 60 ° C. for about 4 hours.

  The stirred reaction mixture was quenched with distilled water and the solvent was removed. The reaction mixture from which the solvent had been removed was redissolved with distilled water and acidified with concentrated hydrochloric acid to pH 5-6.

  After the acidified reaction mixture was concentrated again, methanol was added and the slurry was filtered to remove inorganic salts. The filtrate was washed twice with hexane, the methanol layer was concentrated again, and diethyl ether was added. Crystallized.

The white solid obtained by crystallization was vacuum-dried and the structure was confirmed by ¹ H NMR. Difluorohydroxypropane sulfonic acid sodium salt, sodium 3-ethyoxy-1,1-difluor-3-oxopropane-1-sulfonate (“A” in the following reaction formula 1) 68. Yield 95%) was obtained.

¹ H-NMR (chloroform-d3, internal standard: tetramethylsilane): (ppm) 3.3 (t, 2H), 4.58 to 4.68 (t, 2H)

  In the above formula, Me represents a methyl group, and Et represents an ethyl group.

2) Synthesis of 2-methylacrylic acid-2,2-difluoro-2-sulfopropyl ester sodium salt (2-Methyl-acrylic acid-2, 2-difluoro-2-sulfo-propyl ester sodium salt) Synthesis of the above compound Example 1) Difluorohydroxypropane sulfonic acid sodium salt represented by “A” in Reaction Scheme 1 (sodium 3-ethyoxy-1,1-difluoro-3-oxopropane-1-sulfurone) ) 68 g and methacryloyl chloride (54.6 ml) are mixed with dichloromethane (MC) (500 ml). Then, 3.2 g of N, N′-dimethylaminopyridine (NMAP) and 50 mg of a polymerization inhibitor (Hydroquinone Monoethyl Ether, MEHQ) were added and mixed at 15 to 25 ° C. 104 ml of triethylamine (Et ₃ N) prepared in advance at 15 to 25 ° C. was gradually added dropwise using a dropping funnel to prepare a reaction mixture. The reaction mixture was stirred at 15 to 25 ° C. for 3 hours, and the reaction was terminated by judging the progress of the reaction by NMR.

After completion of the reaction of the reaction mixture, dichloromethane as a reaction solvent was distilled off under reduced pressure, 300 ml of distilled water was added, and potassium carbonate was added to make a saturated solution. The solid produced by stirring the saturated solution for 2 hours was filtered, and 2-methylacrylic acid-2,2-difluoro-2-sulfopropyl ester sodium salt represented by “B” in the following reaction formula 2 (2-Methyl) -Acrylic acid-2,2-difluoro-2-sulfo-propylester sodium salt, sodium 1,1-difluoro-3- (methacryloyloxy) propane-1-sulfonate 81g (yield: 86%) was obtained. The structure was confirmed by ¹ H NMR.

¹ H-NMR (DMSO, internal standard: tetramethylsilane): (ppm) 1.91 (s, 3H), 3.3 (t, 2H), 4.57 to 4.67 (t, 2H), 5 .77 (s, 1H), 6.11 (s, 1H)

  In the above formula, Et means an ethyl group.

3) 2-Methylacrylic acid-2,2-difluoro-2-sulfopropyl ester diphenylmethylphenylsulfonium salt (2-Methyl-acrylic acid-2, 2-difluoro-2-sulfo-propyl ester diphenylsulfurium salt) Synthesis 2-methylacrylic acid-2,2-difluoro-2-sulfopropyl ester sodium salt prepared according to Synthesis Example 2) of the above compound (2-Methyl-acrylic acid-2,2-difluoro-2-sulfo-propyl ester) sodium salt, sodium 1,1-difluoro-3- (methacryloyloxy) propan-1-sulfonate) 31 Then, 35 g of diphenylmethylphenylsulfonium trifluoromethanesulfonium salt represented by “C” in the following reaction formula 3 is dissolved in 300 ml of dichloromethane (MC) and 300 ml of distilled water to prepare a reaction mixture. Stir vigorously for 3 hours by layer reaction.

When the stirring was completed, the organic layer was taken, the progress of the reaction was confirmed by ¹⁹ F NMR, and the reaction was terminated. The organic layer of the reaction mixture after completion of the reaction is collected to remove the solvent, washed with dichloromethane of good solvent and hexane of poor solvent, and the solvent is removed to obtain crystals. It was.

The crystals from which the solvent had been removed were dried under reduced pressure and 2-methylacrylic acid-2,2-difluoro-2-sulfopropyl ester diphenylmethylphenylsulfonium salt (2-Methyl-acrylic salt) represented by “D” in the following reaction formula 3. 40 g (yield 96%) of acid-2,2-difluoro-2-sulfo-propyl ester diphenyl methylsulfone salt was obtained, and its structure was confirmed by ¹ H NMR.

¹ H-NMR (chloroform-d3, internal standard: tetramethylsilane): (ppm) 1.95 (s, 3H), 2.43 (s, 3H), 3.3 (t, 2H), 4.82 (T, 2H), 5.60 (s, 1H), 6.22 (s, 1H), 7.43-7.80 (m, 14H)

<Polymer synthesis example>
Example 1
Polymerization monomers 2-methyl 2-adamantyl acrylate (2-methyl 2-adamantyl acrylate), γ-butyrolactyl methacrylate (γ-butyrolactyl methacrylate), 3-hydroxy 1-adamantyl methacrylate (3-hydroxy 1-adamantyl methacrylate) 2-methylacrylic acid-2,2-difluoro-2-sulfopropyl ester diphenylmethylphenylsulfonium salt (2-Methyl-acrylic acid-2, 2-difluoro-) represented by “D” in Reaction Scheme 3 above. 2-sulfo-propyl ester diphenyl methyl sulfate salt) 13g, 8.4g, 11.6 respectively It was prepared monomer mixture solution by dissolving 1g of 1,2-dichloroethane (1,2-dichloroethane) 58g.

  Nitrogen gas in a reaction vessel containing 3.7 g of norbornene, 2.5 g of polymerization initiator azobisisobutyronitrile (AIBN), and 117 g of polymerization solvent 1,2-dichloroethane in a 250 ml flask. And stirred for 1 hour while maintaining 15 to 25 ° C.

  The temperature of the reaction vessel was maintained at 65 ° C., and the monomer mixture was gradually added dropwise over 1 hour to produce a reaction mixture, which was reacted for 16 hours. The reaction mixture after completion of the polymerization was cooled to 15 to 25 ° C., precipitated with hexane and filtered. During the filtration, the crystals were washed several times with the same solvent and dried under reduced pressure to obtain 37 g (yield 79%) of the polymer of Example 1 represented by the following chemical formula 11. In the polymer of Example 1 represented by the following chemical formula 11, l is 0.24, m is 0.25, n is 0.30, o is 0.20, and p is 0.01.

  The polymer of Example 1 had a polystyrene-reduced weight average molecular weight (Mw) of 1,190 and a molecular weight distribution (ratio of weight average molecular weight to number average molecular weight, Mw / Mn) of 1.57.

(Example 2)
Manufactured in the same manner as in Example 1, except that the values of l, m, n, o and p in Formula 11 are different from those in Example 1 by adjusting the amount of each monomer for polymerization. did. The polymer of Example 2 has l, m, n, o, and p values of Formula 11 with l being 0.24, m being 0.25, n being 0.30, o being 0.18, and p was set to 0.03.

(Example 3)
Manufactured in the same manner as in Example 1, except that the values of l, m, n, o and p in Formula 11 are different from those in Example 1 by adjusting the amount of each monomer for polymerization. did. The polymer of Example 3 has the values of l, m, n, o, and p in Formula 11 with l being 0.24, m being 0.25, n being 0.30, o being 0.16, and p was set to 0.05.

(Example 4)
Manufactured in the same manner as in Example 1, except that the values of l, m, n, o and p in Formula 11 are different from those in Example 1 by adjusting the amount of each monomer for polymerization. did. The polymer of Example 4 has the values of l, m, n, o, and p in Formula 11 with l being 0.24, m being 0.25, n being 0.30, o being 0.14, and p was set to 0.07.

(Comparative example)
Polymerization monomers 2-methyl 2-adamantyl methacrylate (2-methyl 2-adamantyl methacrylate), γ-butyrolactyl methacrylate (γ-butyryl lactyl methacrylate), 3-hydroxy 1-adamantyl methacrylate (3-hydroxy 1-adamantyl) 10.0 g, 7.3 g, and 10.1 g each were mixed and dissolved in 82 g of 1,4-dioxane to produce a monomer mixture, and the tank temperature was gradually increased to 65. Raised to ° C.

  Nitrogen gas was introduced into a reaction vessel in which 3.7 g of norbornene, 2.5 g of polymerization initiator azobisisobutyronitrile (AIBN) and 117 g of polymerization solvent 1,2-dichloroethane were placed in a 250 ml flask. The mixture was poured and stirred for 1 hour while maintaining 15 to 25 ° C.

  The temperature of the reaction vessel was maintained at 65 ° C., and the monomer mixture was gradually added dropwise over 1 hour to produce a reaction mixture, which was reacted for 16 hours. The reaction mixture after completion of the polymerization was cooled to 15 to 25 ° C., precipitated with hexane and filtered. During the filtration, the crystals were washed several times with the same solvent and dried under reduced pressure to obtain 25 g (yield 91%) of a polymer represented by the following chemical formula 12.

  In the following chemical formula 12, the l is 0.28, the m is 0.24, the n is 0.24, and the o is 0.24.

  The polymer represented by the following chemical formula 12 had a polystyrene equivalent weight average molecular weight (Mw) of 1,780 and a molecular weight distribution (ratio of weight average molecular weight to number average molecular weight, Mw / Mn) of 1.68.

<Manufacture of resist and evaluation of physical properties>
Example 1
After dissolving 0.75 part by weight of tetramethylammonium hydroxide as a basic additive in 100 parts by weight of the polymer of Example 1 in 1,000 parts by weight of propylene glycol methyl ether acetate, A resist solution was produced by filtration through a 0.2 μm membrane filter.

  The resist solution was applied onto a substrate using a spinner and dried at 110 ° C. for 90 seconds to form a 0.2 μm thick film. The formed film was exposed using an ArF excimer laser stepper (lens numerical aperture: 0.75) and heat-treated at 120 ° C. for 90 seconds. The heat-treated substrate was developed with a 2.38 wt% tetramethylammonium hydroxide aqueous solution for 40 seconds, washed and dried to form a resist pattern.

(Examples 2 to 4)
In the manufacture of the resist and the evaluation of physical properties, 100 parts by weight of the polymers synthesized in Examples 2 to 4 of the respective polymer synthesis examples were used in place of 100 parts by weight of the polymer of Example 1, and the resist was produced. The physical property evaluation method was the same as in Example 1, and a resist pattern was formed to evaluate the physical properties.

(Comparative Examples 1-3)
Using the polymer of the comparative example represented by the chemical formula 12, a resist solution is produced with the composition shown in Table 1 below, and the resist production and physical property evaluation methods are the same as in Example 1 to form a resist pattern. The physical properties were evaluated.

(1) Acid generator: Triphenylsulfonium nonaflate (Triphenylsulfonium nonaflate)
(2) Basic additive: Tetramethylammonium hydroxide (Tetramethylammonium hydroxide)
The physical properties of Examples 1 to 4 and Comparative Examples 1 to 3 are shown in Table 2 below after evaluating sensitivity, resolution, and LER.

  The sensitivity is resolved when the exposure amount for forming a 0.10 um line-and-space (L / S) pattern formed after development with a 1: 1 line width is the optimum, and the optimum exposure amount is the sensitivity. The size of the smallest pattern is displayed as the resolution.

  LER was measured by CD SEM, and the evaluation results were divided into 5 levels and expressed as 1 (very bad), 2 (bad), 3 (normal), 4 (good), and 5 (very good).

  Referring to Table 2, the sensitivity and resolution of Examples 1 to 4 are generally superior to those of Comparative Examples 1 to 3, and in particular, LER is superior to Examples 1 to 4 in comparison with Comparative Examples. .

  The preferred embodiment of the present invention has been described in detail above, but the scope of the present invention is not limited to this, and the basic concept of the present invention defined in the following claims is used. Various modifications and improvements of the traders are also within the scope of the present invention.

Claims (3)

A polymer represented by the following chemical formula 4 .

In the above formula,
R ₁₁ , R ₁₂ , R ₁₃ , R ₁₄ , R ₁₅ , R ₄₁ , R ₄₂ , R ₄₃ , R ₄₄ , R ₄₅ , R ₄₆ , R ₄₇ , R ₄₈ and R ₄₉ are each independently hydrogen, carbon number Any one selected from the group consisting of alkyl having 1 to 10, perfluoroalkyl having 1 to 10 carbons, and alkoxy having 1 to 10 carbons;
Q ₁ and Q ₂ are each independently a halogen atom ,
R ₂₁ , R ₂₂ and R ₂₃ are each independently selected from the group consisting of hydrogen, alkyl groups, heteroalkyl groups, cycloalkyl groups, heterocycloalkyl groups, aryl groups, heteroaryl groups, and combinations thereof. Or one,
A + is an organic counter ion ,
The l, m, n, o and p are 0 <l ≦ 0.4, 0 <m ≦ 0.5, 0 ≦ n ≦ 0.5, 0 ≦ o ≦ 0.5, 0 <p ≦ 0. 2 and l + m + n + o + p = 1 ,
R ₃₁ is a hydrogen atom,
Said b is an integer of 0-5, and said c is an integer of 0-8.   The polymer according to claim 1, wherein the polymer has a weight average molecular weight of 2,000 to 100,000 and a molecular weight distribution of 1.5 to 5.   A chemically amplified resist composition comprising the polymer according to claim 1.